Duet from the operetta "Cagliostro in Wien" ("Cagliostro in Vienna") Duet from the operetta "Cagliostro in Wien" ("Cagliostro in Vienna") composer Johann Strauss (Sohn) Libretto Richard Genée Libretto F. Zell Main opus "Cagliostro in Wien" ("Cagliostro in Vienna"), operetta in 3 acts